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1.
Ital J Pediatr ; 47(1): 125, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078407

RESUMO

INTRODUCTION: Acute pediatric poisoning is an emerging health and social problem. The aim of this study is to describe the characteristics of a large pediatric cohort exposed to xenobiotics, through the analysis of a Pediatric Poison Control Center (PPCc) registry. METHODS: This study, conducted in the Pediatric Hospital Bambino Gesù of Rome, a reference National Pediatric Hospital, collected data of children whose parents or caregivers contacted the PPCc by phone (group "P"), or who presented to the Emergency Department (group "ED"), during the three-year period 2014-2016. Data were prospectively and systematically collected in a pre-set electronic registry. Comparisons among age groups were performed and multivariable logistic regression models used to investigate associations with outcomes (hospital referral for "P", and hospital admission for "ED"group). RESULTS: We collected data of 1611 children on group P and 1075 on group ED. Both groups were exposed to both pharmaceutical and non-pharmaceutical agents. Pharmaceutical agent exposure increased with age and the most common route of exposure was oral. Only 10% among P group were symptomatic children, with gastrointestinal symptoms. Among the ED patients, 30% were symptomatic children mostly with gastrointestinal (55.4%) and neurologic symptoms (23.8%). Intentional exposure (abuse substance and suicide attempt), which involved 7.7% of patients, was associated with older age and Hospital admission. CONCLUSIONS: Our study describes the characteristics of xenobiotics exposures in different paediatric age groups, highlighting the impact of both pharmacological and intentional exposure. Furthermore, our study shows the utility of a specific PPCc, either through Phone support or by direct access to ED. PPCc phone counselling could avoid unnecessary access to the ED, a relevant achievement, particularly in the time of a pandemic.


Assuntos
Centros de Controle de Intoxicações , Intoxicação/epidemiologia , Adolescente , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Feminino , Hospitalização/estatística & dados numéricos , Linhas Diretas , Humanos , Lactente , Recém-Nascido , Itália/epidemiologia , Masculino , Estudos Prospectivos , Sistema de Registros , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Tentativa de Suicídio/estatística & dados numéricos
2.
Phys Chem Chem Phys ; 12(36): 10786-92, 2010 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-20635004

RESUMO

The electrochemical properties of the I(3)(-)/I(-) reaction mediator as a function of temperature in the range from 30 degrees C to 80 degrees C were investigated by means of symmetric Pt electrodes thin-layer cells (TLC), using three electro-analytical techniques: Electrochemical Impedance Spectroscopy (EIS), Slow Scan Cyclic Voltammetry (SSCV) and Chronoamperometry (CA). Our study pointed out that raising the cell temperature has a beneficial effect both on charge transfer and on mass transport, with an activation energy for the electron transfer process at equilibrium of 24 kJ mol(-1), and of 12 kJ mol(-1) for the mass transfer process at equilibrium. Viscosity and conductivity measurements have demonstrated that most of the ionic mass transport in the solvent (methoxypropionitrile) follows the Stokes' law and that the Walden product is constant, in the temperature range investigated. The diffusion of I(3)(-), however, was found to be partly "non-Stokesian" at lower temperature where the viscosity of the electrolyte is higher. We have shown that EIS and chronoamperometry are both valid methods to derive diffusion coefficients of redox ions in TLC, even if their exact concentration in the electrolyte is not known.

3.
Lett Appl Microbiol ; 51(5): 586-94, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20875035

RESUMO

AIMS: To evaluate interactions between Lactobacillus sakei and coagulase negative cocci (CNC) (Staphylococcus xylosus and Kocuria varians) and to investigate the influence of these interactions on their own proteolytic activity. METHODS AND RESULTS: Interactions occurring between strains of Lact. sakei and CNC were assessed by spectrophotometric analysis. The growth of 35 strains of Lact. sakei, used as indicators, was compared to that obtained combining the same strains with growing cells or cell-free supernatants of 20 CNC (18 Staph. xylosus and 2 K. varians). The proteolytic activity expressed by single strains or by their combinations was assessed on sarcoplasmic protein extracts by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The results evidenced that interactions are able to affect not only the growth but also the in vitro proteolytic activity of Lact. sakei and CNC used in combination. CONCLUSIONS: A relationship between the presence of interactions among useful strains and the strength of technological characteristics, such as proteolysis, was defined. SIGNIFICANCE AND IMPACT OF THE STUDY: The study highlighted that CNC are able to stimulate the growth of some Lact. sakei strains. At the same time, this interaction positively influences the proteolytic activity of strains used in combination. Given the importance of proteolysis during the ripening of fermented meats, this phenomenon should be taken into account to select meat starter cultures.


Assuntos
Proteínas de Bactérias/metabolismo , Lactobacillus/enzimologia , Lactobacillus/crescimento & desenvolvimento , Staphylococcus/enzimologia , Staphylococcus/crescimento & desenvolvimento , Animais , Eletroforese em Gel de Poliacrilamida , Fermentação , Lactobacillus/química , Lactobacillus/metabolismo , Produtos da Carne/microbiologia , Staphylococcus/química , Staphylococcus/metabolismo
4.
Poult Sci ; 89(9): 1975-80, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20709984

RESUMO

To investigate the possibility to carry pathogen bacteria in turkey flocks via cryopreserved semen, research was carried out 1) to investigate the microbial contamination of fresh and frozen thawed turkey semen and 2) to evaluate the effect of the freezing-thawing process on the survival of 3 serovars of Salmonella spp. experimentally inoculated in turkey semen. Five pools of semen diluted 4-fold were cooled, added with 8% of dimethylacetamide as a cryoprotectant, and aliquots of 80 muL were directly plunged into liquid nitrogen to form frozen pellets. Mesophilic viable counts, total and fecal coliforms, Enterobacteriaceae, enterococci, Campylobacter spp., and Salmonella spp. were investigated on fresh and thawed samples. Further, 5 pools of diluted semen were each divided into 3 subsamples, inoculated with 7.8 +/- 0.2 log cfu.mL(-1) of Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup, respectively, and cryopreserved before to assess the postthaw viability of Salmonella spp. strains. Fresh semen was highly contaminated by all of the saprophytic bacteria investigated and the cryopreservation process reduced the amount of mesophilic viable count and total coliforms (P < 0.05) and fecal coliforms, Enterobacteriaceae, and enterococci (P < 0.01) by about 1 log cfu.mL(-1). Conversely, neither Campylobacter spp. nor Salmonella spp. were found as endogenous bacteria in semen. In the inoculated semen, both Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup colonies were recovered postthaw, showing a significant reduction of 2.03 +/- 0.28, 3.08 +/- 0.22, and 2.72 +/- 0.23 log cfu.mL(-1), respectively, compared with the fresh semen (P < 0.001). In conclusion, the cryopreservation process allowed us to obtain a low reduction of microbial count both in endogenous saprophytic bacteria and artificially inoculated Salmonella spp. strains; therefore, the possibility of Samonella spp. transmission to flocks through the use of infected cryopreserved semen does exist.


Assuntos
Criopreservação/veterinária , Doenças das Aves Domésticas/transmissão , Salmonelose Animal/transmissão , Salmonella/isolamento & purificação , Sêmen/microbiologia , Perus , Animais , Masculino , Doenças das Aves Domésticas/microbiologia , Fatores de Risco
5.
Nanotechnology ; 20(11): 115303, 2009 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-19420437

RESUMO

A prototype low cost table-top Ar capillary discharge laser source (1.5 ns pulse duration, lambda = 46.9 nm) was successfully used to produce, by means of interference lithography (with a simple Lloyd mirror setup), large area (0.1 mm(2)) regular patterns from 400 nm down to 22.5 nm (half-pitch) on PMMA/Si (PMMA: polymethylmethacrylate) substrates. The experiments allowed a systematical investigation of the degree of mutual coherence of the source, giving a clear indication that the interference lithography can be pushed down to the ultimate resolution limit of lambda/4.

6.
Rev Argent Microbiol ; 41(2): 92-6, 2009.
Artigo em Espanhol | MEDLINE | ID: mdl-19623898

RESUMO

Vancomycin-resistant enterococci (VRE) have an important impact on pediatric oncology population. The objectives of this study were: to know the prevalence of VRE intestinal colonization in oncology patients, to identify the risk factors that predispose hospitalized patients to VRE intestinal colonization, and to determine the VRE resistance profile to different antimicrobial agents. We studied all children with oncological disease aged 1 month to 16 years that had joined the protocol and had been hospitalized from October 2006 to April 2007. VRE intestinal colonization was analyzed when the patient was admitted to hospital, 72 hours later, and weekly during hospitalization. A total of 333 samples were taken from 67 patients. From these, VRE were isolated in 12 patients, with a prevalence of 17.9%. Of the 28 isolates studied, taking one per patient, 10 were Enterococcus faecium and 2 Enterococcus faecalis, both with resistance phenotype VanA (CIM90 512 microg/ml to vancomycin and CIM90 256 microg/ml to teicoplanin). The use of vancomycin (p = 0.02), duration of neutropenia greater than 7 days (p = 0.03) and prolonged hospitalization (42.8 days on average) (p = 0.0001) were risk factors significantly related to VRE colonization. We considered it necessary to carry out an epidemiological surveillance and to implement prevention and control measures.


Assuntos
Enterococcus/efeitos dos fármacos , Intestinos/microbiologia , Neoplasias/microbiologia , Resistência a Vancomicina , Adolescente , Antibacterianos/farmacologia , Argentina/epidemiologia , Criança , Pré-Escolar , Infecção Hospitalar/prevenção & controle , Farmacorresistência Bacteriana Múltipla , Enterococcus/isolamento & purificação , Feminino , Infecções por Bactérias Gram-Positivas/prevenção & controle , Hospitais Pediátricos , Humanos , Hospedeiro Imunocomprometido , Lactente , Recém-Nascido , Masculino , Neutropenia/microbiologia , Prevalência , Fatores de Risco
7.
Microsc Res Tech ; 71(3): 179-85, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17992692

RESUMO

This article reports on the first utilization of the soft X-ray beamline at the DaPhine synchrotron light source for mapping the intake of different elements in plant tissues. As a test, the method of dual-energy X-ray microradiography was applied to the investigation of the natural sulfur content in dried leaf and root samples. Our ultimate goal was to monitor the pollutant lead and its intake, which was added in controlled doses to the hydroponic medium of laboratory-controlled samples of vegetal species. The results obtained by the nondestructive X-ray radiographic analysis are compared to the values of concentrations determined by a standard chemical analysis utilizing atomic absorption spectroscopy. From this comparison the validity of the X-ray detection of heavy metals in biological samples has been confirmed. The superposition of the dual energy results on the simple planar radiography shows the representation of the pollutant intake directly on the sample structures. It should be pointed out that this method, developed here for plant root and leaves could be applied to any biological sample of interest, but the preparation and observation conditions necessitate different strategies according to the type of sample under analysis.


Assuntos
Chumbo/análise , Pisum sativum/química , Enxofre/análise , Zea mays/química , Iluminação , Microrradiografia , Folhas de Planta/química , Raízes de Plantas/química , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/instrumentação , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Espectrofotometria Atômica , Síncrotrons/instrumentação , Raios X
8.
Rev Argent Microbiol ; 40(2): 111-5, 2008.
Artigo em Espanhol | MEDLINE | ID: mdl-18705494

RESUMO

The purpose of our research was to know the frequency of microorganisms causing bacteremia and/or fungemia in oncology patients from Hospital de Niños de Córdoba, as well as to describe the antimicrobial susceptibility patterns of bacteria isolated from January 2006 to April 2007. A total of 59 bacteremia and fungemia cases in 44 patients were studied. From the total number of isolations, 45.8% were gram-negative bacilli, 35.6% were gram-positive cocci, and 18.6% were yeasts. The global distribution of the most prevalent microorganisms was the following: Klebsiella spp. 15.3%; Staphylococcus aureus and Candida parapsilosis 11.9%; coagulase-negative staphylococci 10.2%; Escherichia coli 8.5%, and Pseudomonas aeruginosa 6.8%. More than 40% (41.2%) of enterobacteria showed an extended-spectrum beta-lactamase phenotype, and 20.0% of non-fermenting gram-negative bacilli were multi-resistant to tested antibiotics, while 38.5% of Staphylococcus spp. were methicillin-resistant. In conclusion, the most prevalent microorganisms were gram-negative bacilli, and within this group, enterobacteria evidenced a higher percentage of resistance to tested antibiotics.


Assuntos
Bacteriemia/complicações , Bacteriemia/microbiologia , Fungemia/complicações , Fungemia/microbiologia , Neoplasias/complicações , Bacteriemia/epidemiologia , Criança , Pré-Escolar , Feminino , Fungemia/epidemiologia , Humanos , Masculino , Testes de Sensibilidade Microbiana , Prevalência
9.
Mediterr J Hematol Infect Dis ; 10(1): e2018037, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30002793

RESUMO

Kawasaki disease (KD) is an acute, self-limited, inflammatory disease affecting medium-sized arteries and particularly the coronary arteries in about 25% of untreated cases. KD is a clinical diagnosis based on the presence of ≥5 days of fever and the presence of ≥4 of the 5 principal clinical criteria. We described, for the first time to our knowledge, a case of a very early development (on day 1) of typical KD with transient coronary involvement, diagnosed on day 2 of disease and treated with aspirin and steroids on day 3, with complete resolution of clinical signs and coronary involvement.

11.
Biochim Biophys Acta ; 1173(2): 209-16, 1993 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-8504169

RESUMO

H1 exerts a specific in vitro inhibitory effect on enzymic DNA methylation. The experiments reported in this paper were undertaken in order to assess whether the lower methylation level found in internucleosomal DNA compared to core DNA is the in vivo consequence of the well-known localization of this histone in the linker region, as opposed to a possible deficiency of CpG dinucleotides in linker DNA. The methyl-accepting ability of H1-depleted oligonucleosomes from human placenta and of the corresponding core particles were assayed by addition of purified DNA methyltransferase, using S-adenosylmethionine as the methyl group donor. We have found that approx. 80% of newly-incorporated methyl groups are localized in linker DNA, which is indeed a good potential substrate for enzymic DNA methylation. Addition of quasi-physiological amounts of H1 to H1-depleted oligonucleosomes markedly reduced their methyl-accepting ability, while exerting a re-condensing effect on these particles, as revealed by the distortions of their circular dichroism spectra.


Assuntos
Cromatina/metabolismo , Histonas/fisiologia , DNA/metabolismo , Fosfatos de Dinucleosídeos/metabolismo , Humanos , Metilação , Nucleossomos/metabolismo , Placenta
12.
Biochim Biophys Acta ; 1090(1): 38-42, 1991 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-1883842

RESUMO

Histones (from calf thymus or from human placenta), if renatured in the presence of EDTA, caused a severe inhibition of in vitro methylation of double-stranded DNA (from Micrococcus luteus) by human placenta DNA methyltransferase. The absence of EDTA during the histone renaturation procedure abolished--at least in the 'physiological' range of the histones/DNA ratio--the inhibition. The H1 component was responsible for this inhibition, no effect being exerted by the other histones. H1 preparations were more effective if renatured in the presence of EDTA--90% inhibition being reached at a 0.3:1 (w/w) H1/DNA ratio. It seems likely that the requirement for the presence of EDTA during the renaturation process is correlated to its ability to induce a fairly stable ordered conformation of the histones, although this effect could also be shown with the 'inactive' H2a, H2b and H3 components, and was instead less evident with histone H1. The restriction to histone H1 of the ability to inhibit enzymic DNA methylation may account for the lower methylation levels present in the internucleosomal DNA of mammalian chromatin.


Assuntos
Cromatina/metabolismo , Metilases de Modificação do DNA/antagonistas & inibidores , DNA Bacteriano/metabolismo , Histonas/metabolismo , Animais , Bovinos , Dicroísmo Circular , Metilases de Modificação do DNA/metabolismo , Humanos , Metilação , Micrococcus/genética , Placenta/enzimologia , Espectrofotometria Ultravioleta
13.
Biochim Biophys Acta ; 1129(1): 43-8, 1991 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-1756179

RESUMO

After removal, by high-salt extraction, of the loosely-bound components present in human placenta chromatin, tightly-bound cationic proteins could be solubilized, by acid extraction, from the 'stripped' chromatin, as well as from the 'stripped' loops or from the 'digested matrix'. These acid-soluble tightly-bound proteins are, in terms of apparent molecular mass and immunoreactivity, quite similar to the 'typical', loosely-bound histones, and, similarly to their 'loosely-bound' counterparts, they can be subdivided in distinct H1-, H2A-, H2B-, H3- and H4-like components, the 'digested matrix' being however characterized by the absence of tightly-bound H1. These tightly-bound histones, at variance from the 'typical' ones, readily find a right-handed helical conformation upon renaturation by progressive dialyses. The H1 components strongly differ also in their effects on enzymic DNA methylation: while 'typical' H1 has a strong inhibitory effect, its tightly-bound counterpart exerts a slight but definite stimulation.


Assuntos
Cromatina/metabolismo , Metilases de Modificação do DNA/metabolismo , Histonas/metabolismo , Cromatina/química , Dicroísmo Circular , Histonas/química , Histonas/isolamento & purificação , Humanos , Metilação , Conformação de Ácido Nucleico , Espectrofotometria Ultravioleta
14.
J Am Coll Cardiol ; 19(6): 1173-9, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1564218

RESUMO

To assess the long-term prognostic significance of total ischemic time (silent plus painful ischemia) and silent ischemia in patients with unstable angina whose condition stabilized with medical treatment, 76 patients were studied. All patients underwent Holter ambulatory electrocardiographic (ECG) monitoring for greater than or equal to 48 h beginning within the 1st 12 h of the hospital stay. Forty-three patients (Group A) had a total ischemic time greater than or equal to 60 min, whereas 33 patients (Group B) had a total ischemic time less than 60 min. More than 78% of the ischemic episodes in patients in Group A and 62% of those in Group B were silent (p less than 0.05); nine patients in Group A and six in Group B had only silent episodes. Patients in Group A frequently showed three-vessel disease (65% vs. 18%, p less than 0.01), angiographic findings of subtotal occlusion of the coronary arteries (TIMI grade I) (76.7% vs. 42.4%, p less than 0.01) and ischemic alterations in the rest ECG (51.2% vs. 30.3%, p less than 0.05). During a 6-year follow-up period, 15 patients in Group A and 8 in Group B experienced myocardial infarction (p less than 0.05); 9 patients in Group A and 4 in Group B required coronary artery surgery (p less than 0.05) and 10 patients in Group A and 4 in Group B died of cardiac causes (p less than 0.01). Multivariate analysis showed three-vessel disease to be the most important predictor of cardiac mortality and morbidity (p = 0.025); it was followed in predictive power by a total ischemic time greater than or equal to 60 min and by left ventricular dysfunction. The presence of silent ischemia was not shown to be an independent predictor of long-term morbidity and mortality. In conclusion, patients with unstable angina and a total ischemic time greater than or equal to 60 min frequently have silent ischemic episodes on Holter ECG monitoring, a greater extent of coronary atherosclerosis and ischemic alterations of the rest ECG. The long-term prognosis of patients with unstable angina whose condition stabilizes with medical treatment depends on the extent of coronary atherosclerosis and on the longer duration of total ischemic time but not on the presence of silent ischemia.


Assuntos
Angina Instável/epidemiologia , Doença das Coronárias/epidemiologia , Análise Atuarial , Adulto , Angina Instável/diagnóstico , Angina Instável/mortalidade , Distribuição de Qui-Quadrado , Angiografia Coronária , Doença das Coronárias/diagnóstico , Doença das Coronárias/mortalidade , Eletrocardiografia Ambulatorial , Seguimentos , Humanos , Itália/epidemiologia , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/mortalidade , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Tempo
15.
FEMS Microbiol Lett ; 244(1): 129-37, 2005 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-15727832

RESUMO

This study aimed to compare phenotypic and genetic characteristics of Lactobacillus rhamnosus strains isolated at the end of the ripening of Parmigiano Reggiano cheese and to investigate an important prerequisite of probiotic interest, such as the capability to survive at low pH and in presence of bile salts. The use of API 50 CH, RAPD-PCR analysis and species-specific PCR allowed to ascertain the identity of 63 L. rhamnosus strains. Three L. rhamnosus strains isolated from Parmigiano Reggiano cheese, L. rhamnosus ATCC 7469T and the commercial strain L. GG were assayed to estimate the resistance to various stress factors reproducing in vitro some conditions of the gastro-intestinal environment such as low pH and different amounts of bile salts and acids. The behaviour of almost all the tested strains isolated from Parmigiano Reggiano cheese resulted analogous to that showed by L. GG.


Assuntos
Ácidos e Sais Biliares/farmacologia , Queijo/microbiologia , Microbiologia de Alimentos , Lactobacillus/efeitos dos fármacos , Lactobacillus/isolamento & purificação , Probióticos , Sequência de Bases , DNA Bacteriano/genética , Concentração de Íons de Hidrogênio , Lactobacillus/genética , Fenótipo , Técnica de Amplificação ao Acaso de DNA Polimórfico
16.
J Food Prot ; 68(12): 2686-92, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16355843

RESUMO

The aim of this study was to investigate differences in modified atmosphere packaging (MAP) for the improvement of the shelf life of fresh meat products. Three different conditions for preserving fresh sausages were tested: MAP1 (20% CO2, 70% O2, and 10% N2), MAP2 (40% CO2 and 60% O2), and MAP3 (40% CO2, 30% O2, and 30% N2). Samples from the MAP2 group had fewer spoilage bacteria, stable red color (no change of a* value), and good physical attributes (high water-holding capacity, little loss from cooking, and low shear force needed for cutting) compared with samples from other treatment groups. Thus, high concentrations of CO2 (40%) and O2 (60%) resulted in a longer shelf life for fresh sausages.


Assuntos
Bactérias/crescimento & desenvolvimento , Embalagem de Alimentos/métodos , Conservação de Alimentos/métodos , Produtos da Carne/microbiologia , Produtos da Carne/normas , Aerobiose , Animais , Dióxido de Carbono/metabolismo , Qualidade de Produtos para o Consumidor , Humanos , Oxigênio/metabolismo , Suínos , Paladar , Fatores de Tempo , Vácuo
17.
Cardiovasc Res ; 20(10): 721-6, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2431780

RESUMO

Acute occlusions of the proximal left circumflex coronary arteriovenous pedicle were performed in open chest anaesthetised dogs. Twenty eight dogs were randomly allocated to receive acebutolol (3 mg X kg-1 twice daily) or placebo given blindly by mouth for five days; a control group of 14 dogs without any pretreatment underwent the same procedure. Coronary ligations in the randomised study were performed during seven consecutive days, and four dogs were operated on each day. This schedule was chosen in order to measure acebutolol plasma concentrations just before ligation from 60 to 540 min after the last dose of the drug. Long term oral treatment with acebutolol protected against postischaemic ventricular fibrillation and significantly reduced the incidence of both early phase (0-10 min postocclusion) ventricular arrhythmias and ventricular fibrillation. As a result the outcome was significantly improved after 60 min of ischaemia in acebutolol compared with placebo treated animals. The results in the control animals were similar to those in the placebo treated dogs. The protective effect of long term oral treatment with acebutolol lasted for nine hours and was apparently independent of the plasma concentrations of the drug. These data show that improved outcome in this canine model is due to the prevention of ischaemia induced ventricular fibrillation by long term beta adrenoceptor blockade, which is able to overcome the effect, if any, of partial agonist activity of acebutolol. A direct myocardial anti-ischaemic effect might explain the effectiveness of long term oral treatment, which is independent of plasma concentrations of the drug.


Assuntos
Acebutolol/uso terapêutico , Fibrilação Ventricular/prevenção & controle , Acebutolol/administração & dosagem , Acebutolol/sangue , Administração Oral , Animais , Arritmias Cardíacas/prevenção & controle , Complexos Cardíacos Prematuros/prevenção & controle , Doença das Coronárias/complicações , Cães , Feminino , Masculino , Distribuição Aleatória , Fatores de Tempo
18.
Gene ; 157(1-2): 247-51, 1995 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-7607500

RESUMO

The inhibitory effect that H1 histone exerts on the in vitro DNA methylation process, catalysed by mammalian DNA methyltransferase, together with the relative hypomethylation of linker DNA in eukaryotic cells chromatin, suggest that this hypomethylated state of linker DNA can be of importance in allowing or regulating H1-dependent chromatin condensation. In native oligonucleosomes (olnu), i.e., in chromatin fragments consisting of 5-20 nucleosomes each, there was a correlation between the effects of H1 on the DNA ellipticity at 280 nm and the in vitro assayed methyl-accepting ability. The same was true in H1-depleted or in H1-reconstituted preparations. Artificial methylation caused olnu DNA to lose its ability to allow cooperative H1-H1 interactions under ionic strength conditions similar to those known to affect the transition of the 10-nm filament to the 30-nm chromatin fiber. These results suggest that hypomethylation of linker DNA plays a role in the H1-H1 interactions that are needed for solenoid condensation.


Assuntos
Cromatina/fisiologia , DNA/química , DNA/metabolismo , Mutagênese Insercional , Animais , Cromatina/ultraestrutura , Dicroísmo Circular , DNA/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Feminino , Histonas/metabolismo , Humanos , Mamíferos , Metilação , Nucleossomos/fisiologia , Nucleossomos/ultraestrutura , Placenta/metabolismo , Gravidez
19.
Gene ; 157(1-2): 253-6, 1995 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-7607502

RESUMO

Upon HPLC fractionation of human placenta or calf thymus H1 histone preparations, only some fractions enriched in the H1e-c variants were able to exert a severe inhibition on in vitro enzymatic DNA methylation. These fractions, though similar to the other variants in interacting with genomic DNA, were also the only ones which could bind CpG-rich ds-oligodeoxyribonucleotides (oligos). Both the 6-CpG ds-oligo and the DNA purified from chromatin fractions enriched in 'CpG islands' were good competitors for the binding of H1e-c to the 6meCpG ds-oligo. This ability to bind any DNA sequence and to suppress the enzymatic methylation in any sequence containing CpG dinucleotides suggests, for these particular H1 variants, a possible role in maintaining CpG island DNA and linker DNA at low methylation levels.


Assuntos
DNA/metabolismo , Variação Genética , Histonas/genética , Histonas/metabolismo , Oligodesoxirribonucleotídeos/química , Animais , Sequência de Bases , Bovinos , Cromatina/química , Cromatina/metabolismo , DNA/química , DNA/isolamento & purificação , Fosfatos de Dinucleosídeos , Feminino , Histonas/isolamento & purificação , Humanos , Metilação , Dados de Sequência Molecular , Oligodesoxirribonucleotídeos/síntese química , Oligodesoxirribonucleotídeos/metabolismo , Placenta/metabolismo , Gravidez , Timo/metabolismo
20.
Am J Cardiol ; 68(6): 642-7, 1991 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-1877482

RESUMO

The purpose of the present study was to verify whether the electrocardiographic pattern of patients with idiopathic dilated cardiomyopathy (IDC) might be useful in predicting measurements of left ventricular (LV) morphology. A total of 12 electrocardiographic criteria for LV enlargement were evaluated in 67 patients with IDC, aged 14 to 68 years (mean 48), and were correlated to LV wall thickness, volume and mass, as assessed at angiography (all patients) and echocardiography (50 patients). Linear regression analysis showed weak correlations between multiple electrocardiographic criteria and LV wall thickness, volume and mass. Multiple logistic regression analysis showed that total 12-lead QRS amplitude, voltage criteria of Sokolow and Lyon, overshoot and U-wave inversion were the variables significantly related to LV wall thickness, as assessed by angiography (r = 0.55, p less than 0.005) and echocardiography (r = 0.43, p less than 0.025). The sum of T/R-wave ratios, the RV6/RV5 ratio and the Romhilt-Estes score were predictors of LV end-diastolic volume, as determined by angiography (r = 0.83, p less than 0.001) and echocardiography (r = 0.77, p less than 0.005). Total 12-lead QRS amplitude and the sum of T/R-wave ratios were the only independent predictors of LV mass, either angiographically (r = 0.81, p less than 0.001) or echocardiographically measured (r = 0.71, p less than 0.025). It is concluded that a single electrocardiographic criterion for prediction of LV morphology in patients with IDC is barely effective. Multiple electrocardiographic criteria should be utilized to better predict LV mass and distinguish reliably between LV wall thickening and dilatation.


Assuntos
Cardiomiopatia Dilatada/patologia , Eletrocardiografia , Ventrículos do Coração/patologia , Adolescente , Adulto , Idoso , Angiocardiografia , Cateterismo Cardíaco , Volume Cardíaco/fisiologia , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Dilatada/fisiopatologia , Diástole/fisiologia , Ecocardiografia , Feminino , Septos Cardíacos/diagnóstico por imagem , Septos Cardíacos/patologia , Ventrículos do Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Análise de Regressão , Função Ventricular Esquerda/fisiologia
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